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Sample mean
| Glossary of Statistical Terms |
The arithmetic mean of a random sample from a population. it is a statistic commonly used to estimate the population mean. suppose there are n data, {x1, x2, … , xn}. the sample mean is (x1 + x2 + … + xn)/n. the expected value of the sample mean is the population mean. for sampling with replacement, the se of the sample mean is the population standard deviation, divided by the square-root of the sample size. for sampling without replacement, the se of the sample mean is the finite-population correction ((n−n)/(n−1))½ times the se of the sample mean for sampling with replacement, with n the size of the population and n the size of the sample.
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Mean, английский
- The mathematical average of a range of numbers (calculated by dividing the sum total of all the items in the range by the total number of items in the range).
- Среднее (значение).
- The arithmetic average of a set of values. a measure of central tendency of the distribution of a set of replicate results. often abbreviated by an x with a bar over it.
- Среднее значение, среднее. мера усреднения наблюдений выборки, формируемая путем суммирования всех величин и деления полученной суммы на количество наблюдений.
- As a general term implies the medium, but a mean of bad observations can never make a good one.
- [1] an average (e.g., mean high water is the average depth of water at high tide). [2] equidistant from two extremes.
- Среднее значение. если не оговорено иное, означает среднее арифметическое.
- The expected value of a random variable. arithmetic average of a sample.
- A way to calculate the average of a series of numbers
- A way to calculate the average of a series of numbers an average determined by adding up a group of numbers, and then dividing that total by the number of numbers. for example, to calculate the mean of “10, 20, 30, 40, 50”: first, add the numbers (10+20+30+40+50 = 150), then count the numbers (5), then divide the total by the number of numbers (150/5 = 30)
Mean, английский
Mean, английский
Mean, английский
Mean, английский
Mean, английский
Mean (meant, meant), английский
Mean (statistic), английский
Media (estadística)
Mean absolute deviation, английский
Средняя абсолютная девиация (магнитного компаса)
Mean absolute deviation (mad), английский
Mean absolute difference, английский
Средняя абсолютная разность
Mean absolute error, английский
Mean access delay, английский
Mean accumulated down time, английский
Mean accumulated down time (madt), английский
Mean accuracy, английский
Средняя точность; точность в среднем
Mean active repair time, английский
Среднее время ремонта
Mean active repair time (mart), английский
Mean administrative delay, английский
Mean administrative delay (mad), английский
Mean aerodynamic chord, английский
Средняя аэродинамическая хорда
Arithmetic, английский
The art of computation by numbers; or that branch which considers their powers and properties.
Population, английский
- A definable set of individual units to which the findings from statistical examination of a sample subset are intended to be applied. the population will generally much outnumber the sample. in re-randomisation statistics the process of applying inference
- See stock.
- A collection of units being studied. units can be people, places, objects, epochs, drugs, procedures, or many other things. much of statistics is concerned with estimating numerical properties (parameters) of an entire population from a random sample of units from the population.
- A group or number of people living within a specified area or sharing similar characteristics (such as occupation or age).
- Население; народонаселение; генеральная совокупность (в выборочном наблюдении); популяция (биол)
- Население
- 1. the number of people living in a country or town population statistics show that the birth rate is slowing down. the government has decided to screen the whole population of the area. 2. the number of patients in hospital the hospital population in the area has fallen below 10,000.
- Популяция
- Население; популяция -
- Популяция. в клинических исследованиях совокупность субъектов, обладающих какими-либо одинаковыми признаками (пол, возраст, диагноз).
- Население; популяция
- Any group of individuals, usually of a single species, occupying a given area at the same time; groups of organisms with homologue (same) alleles. p. cycle: changes in the numbers of individuals in a population which repeatedly oscillate between periods of high and low density. p. density: allowing a mathematically precise reflection - pd. • absolute: pd = number of individuals/unit area or volume [1/m2] or [1/m3] • relative: pd allows only a simple comparison (pd <, =, >, ? etc.). p. dynamics: the variations in time and space in the sizes and densities of populations; distribution due to changing food resources - the stability of a population depends upon abiotic factors, intraspecific competition (density dependent), natality, mortality etc. p. ecology: the study of the variations in time and space in the sizes and densities of populations, and of the factors causing those variations. p. fluctuation: variations over time in the size of a population. p. growth: is zero, when the birth rate equals the death rate (see carrying capacity). nt+1 = nt + r nt, current number of individuals r = (natality + immigration) - (mortality+emigration) r, intrinsic rate of growth (see density) p. pyramid: a means of illustrating the age structure of a population diagrammatically, by placing the youngest age class at the base and stacking successive age classes above it. p. regulation : a tendency in a population for some factor to cause density to increase when it is low and to decrease nt, momentary number of individuals when it is high. n0, number of individuals at start
- Generally, a collection of individuals with common characteristics. in statistics, a potentially infinite collection of independent (->independence) units that include all units of a specified type with attention paid only to the agggregate (->aggregation) property of the collection. a sample of data drawn from this population is a subset of the units constituting this population and scientific generalizations from such samples are limited by the size of the population originally specified (->model, ->representation).
- The process of scanning content to compile and maintain an index.
- Fish of the same species inhabiting a specified geographic area.
Replacement, английский
- Замена
- Замещение; возмещение; воспроизводство^
- An operation to replace part of the body with an artificial part
- N подстановка replacive a замещающий, подстановочный
- Construction of a new pipe or underground utility located on or off the line of the existing systems, which serves the same function as the old system.
Correction, английский
- Species - an adjustment of the readings of the resistance-type electrical moisture meter to compensate for different species of wood. corrections are tabulated in as/nzs 1080 1:1997
- Любой заметный откат от ранее достигнутого уровня. иногда, коррекцией считают откат не менее 1/3 от предыдущего ценового движения;
- Коррекция, поправка
- Исправление, коррекция, поправка
- Любой заметный откат от ранее достигнутого уровня. иногда коррекцией считают откат не менее 1/3 от предыдущего цено¬вого движения.
- Поправка
- N псхлнгв. исправление correctness n правильность grammatical ~ грамматическая правильность
- Исправление; корректирование; корректировка; коррекция; корректура; введение поправки; поправка
- Поправка; исправление; корректирование о ~ for pull геод. поправка на эксцентриситет блоков (в инварных измерениях); ~ for slope поправка за наклон линии ~ of water стабилизация воды
- Reverse movement, usually downward, in the price of an individual stock, bond, commodity, or index. if prices have been rising on the market as a whole, and then fall dramatically, this is known as a correction within an upward trend. antithesis of a technical rally. see: dip, break.
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Base rate fallacy, английский
The base rate fallacy consists of failing to take into account prior probabilities (base rates) when computing conditional probabilities from other conditional probabilities. it is related to the prosecutor`s fallacy. for instance, suppose that a test for the presence of some condition has a 1% chance of a false positive result (the test says the condition is present when it is not) and a 1% chance of a false negative result (the test says the condition is absent when the condition is present), so the exam is 99% accurate. what is the chance that an item that tests positive really has the condition? the intuitive answer is 99%, but that is not necessarily true: the correct answer depends on the fraction f of items in the population that have the condition (and on whether the item tested is selected at random from the population). the chance that a randomly selected item tests positive is 0.99×f/(0.99×f + 0.01×(1−f)), which could be much smaller than 99% if f is small. see bayes` rule.
Conditional probability, английский
- Suppose we are interested in the probability that some event a occurs, and we learn that the event b occurred. how should we update the probability of a to reflect this new knowledge? this is what the conditional probability does: it says how the additional knowledge that b occurred should affect the probability that a occurred quantitatively. for example, suppose that a and b are mutually exclusive. then if b occurred, a did not, so the conditional probability that a occurred given that b occurred is zero. at the other extreme, suppose that b is a subset of a, so that a must occur whenever b does. then if we learn that b occurred, a must have occurred too, so the conditional probability that a occurred given that b occurred is 100%. for in-between cases, where a and b intersect, but b is not a subset of a, the conditional probability of a given b is a number between zero and 100%. basically, one "restricts" the outcome space s to consider only the part of s that is in b, because we know that b occurred. for a to have happened given that b happened requires that ab happened, so we are interested in the event ab. to have a legitimate probability requires that p(s) = 100%, so if we are restricting the outcome space to b, we need to divide by the probability of b to make the probability of this new s be 100%. on this scale, the probability that ab happened is p(ab)/p(b). this is the definition of the conditional probability of a given b, provided p(b) is not zero (division by zero is undefined). note that the special cases ab = {} (a and b are mutually exclusive) and ab = b (b is a subset of a) agree with our intuition as described at the top of this paragraph. conditional probabilities satisfy the axioms of probability, just as ordinary probabilities do.
- Условная вероятность
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